420
FXUS65 KBYZ 191836
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
1236 PM MDT FRI JUN 19 2026
KEY MESSAGES
- ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS SATURDAY THROUGH
MONDAY. HIGHEST CHANCES FOR PRECIPITATION EAST OF A FORSYTH TO
SHERIDAN WY LINE. GUSTY WINDS, SMALL HAIL, AND HEAVY DOWNPOURS
ARE POSSIBLE WITH ANY THUNDERSTORMS SATURDAY.
- SEASONAL WEATHER CONDITIONS, WITH LOW CHANCES (10-20%) FOR
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS, EXPECTED FOR
THE REST OF THE WORK WEEK.
DISCUSSION
THIS AFTERNOON THROUGH NEXT FRIDAY...
DRY NORTHWEST FLOW OVER THE AREA THIS AFTERNOON WILL BRING A
PLEASANT AND DRY EVENING TO THE FORECAST AREA. OVERNIGHT THE
NORTHWESTERLY JET STREAM WILL SHIFT EAST OF THE AREA ALLOWING
WEAK RIDGING TO DEVELOP OVER THE AREA WITH A MODEST SOUTHWESTERLY
JET WORKING IN FROM THE GREAT BASIN. AS THIS OCCURS ALOFT, A
STRENGTHENING LOW LEVEL JET WILL DEVELOP PULLING LOW LEVEL
MOISTURE NORTH FROM THE SOUTHERN PLAINS, INCREASING MOISTURE
LEVELS ACROSS THE AREA INTO THE DAY TOMORROW. AS THE NOSE OF THE
SOUTHWEST JET STREAM APPROACHES THE AREA IT WILL HELP TO GENERATE
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON
AND EVENING HOURS. CONCERNS WITH CONVECTION TOMORROW ARE GENERALLY
SUB-SEVERE IN NATURE WITH THE BEST CHANCE FOR A STRONGER STORM
RESIDING ALONG THE MT/WY BORDER OF SE MONTANA WHERE SHEAR PROFILES
ARE A BIT BETTER. HOWEVER, THE INCREASED MOISTURE MOVING INTO THE
AREA DOES BOOST PWAT VALUES TO AROUND AN INCH OVER THE SOUTHERN
HALF OF THE FORECAST AREA BRINGING LOCALLY HEAVY DOWNPOURS INTO
PLAY. SLOW STORM MOVEMENT MAY ALSO FACTOR INTO THE HEAVY
PRECIPITATION GAME PLAN WITH STORMS GENERALLY MOVING AT UNDER
15KTS TOMORROW.
WILL NEED TO KEEP AN EYE ON BURN SCAR AREAS IN THIS SCENARIO,
THOUGH STORM COVERAGE IS NOT HIGH ENOUGH TO WARRANT A FLASH FLOOD
WATCH AT THIS TIME. ANOTHER THREAT WILL BE WET MICROBURST WIND
GUSTS GIVEN A SATURATED SOUNDING AND SKINNY CAPE EXTENDING TO OVER
35KFT. STORMS WILL BE ORGANIZED AROUND THE DISTURBANCE ON THE
NOSE OF THE JET, BUT OTHERWISE WILL BE LOOKING AT ISOLATED STORMS
BECOMING MORE SCATTERED IN NATURE FORMING ON OUTFLOW BOUNDARIES
THROUGH THE EVENING.
PRECIPITATION CHANCES WILL LINGER SATURDAY NIGHT INTO SUNDAY
MORNING WITH ENERGY CONTINUING TO LEAK INTO THE AREA FROM THE
SOUTHWEST COMBINING WITH THE RESIDUAL MOISTURE OVER THE REGION.
PROBABILITIES FOR A QUARTER INCH OF RAIN SATURDAY AFTERNOON
THROUGH SUNDAY MORNING ARE ABOVE 40% EAST OF A FORSYTH TO SHERIDAN
LINE AND OVER 70% IN CARTER COUNTY. GIVEN THE ISOLATED TO
SCATTERED NATURE OF THE CONVECTION, THE PROBABILITIES ARE MUTED A
BIT AND REALLY REFLECT THE BETTER COVERAGE AND ORGANIZATION OF
CONVECTION EXPECTED OVER SE MONTANA COMPARED TO AREAS FURTHER WEST.
WPC HAS SE MONTANA IN A MARGINAL RISK FOR EXCESSIVE RAINFALL FOR
SATURDAY AND SUNDAY WHICH REFLECTS A 5% CHANCE FOR EXCEEDING FLASH
FLOOD GUIDANCE IN THIS AREA.
BASED ON THE FORECAST SOUNDINGS, IF YOU GET UNDER ONE OF THESE
HEAVY SLOW MOVING STORMS A QUICK HALF INCH TO AN INCH OF
PRECIPITATION IS A REAL POSSIBILITY. THE SOUNDINGS ALSO SHOW THE
HEAVY DOWNPOUR POTENTIAL EXISTS WESTWARD INCLUDING BILLINGS AND
MAYBE EVEN BACK THROUGH BIG TIMBER, THOUGH THE FURTHER WEST YOU GO
THE FASTER THE STORM MOVEMENT AND THE LOWER THE PWATS. STILL IF
YOU HAVE OUTDOOR PLANS TOMORROW EVEN OVER THE WESTERN FOOTHILLS,
BE AWARE THAT LOCALLY HEAVY DOWNPOURS ARE POSSIBLE ALONG WITH THE
GUSTY WET MICROBURST TYPE WINDS, AND HAVE A PLAN TO GET TO A
STURDY SHELTER IF NECESSARY.
SUNDAY WILL REMAIN UNSETTLED WITH THE SOUTHWESTERLY JET
SAGGING AWAY FROM THE AREA AS A WEAK CANADIAN DISTURBANCE CROSSES
THE NORTHERN PORTION OF THE STATE. THIS WILL WILL PUSH NORTHWEST
WINDS INTO THE AREA IN THE AFTERNOON. THIS DRIER NORTHWESTERLY
FLOW WILL DECREASE THE AVAILABLE MOISTURE IN THE ATMOSPHERE AND
TAKE THE EDGE OFF OF THUNDERSTORM POTENTIAL, THOUGH A FEW ARE
STILL POSSIBLE MAINLY OVER THE EASTERN HALF OF THE FORECAST AREA.
MORE ENERGY WRAPS INTO THE AREA FROM THE NORTH BRINGING ANOTHER
ROUND OF SHOWERS AND ISOLATED THUNDERSTORMS FOR SUNDAY NIGHT INTO
MONDAY AFTERNOON. AGAIN, WITH LOWER PWATS (AROUND 0.5-0.75IN) THIS
ACTIVITY WILL RESULT IN GENERALLY LESS THAN 0.15 INCHES FROM
SUNDAY NIGHT THROUGH MONDAY.
FORECAST MAINLY DRIES OUT FOR THE REST OF NEXT WEEK AS THE PATTERN
ALOFT SHOWS WEAK RIDGING AND A LACK OF ANY STRONGER DISTURBANCES
UNTIL MAYBE FRIDAY NIGHT. RESIDUAL MOISTURE AND GOOD SUNSHINE EACH
DAY WILL PRODUCE ISOLATED LATE DAY CONVECTION (MAINLY OFF THE
MOUNTAINS/FOOTHILLS) BUT THIS ACTIVITY LOOKS WEAK AND SHOULDN'T
POSE A SIGNIFICANT IMPACT TO OUTDOOR PLANS.
TEMPERATURES WILL BE NEAR SEASONAL LEVELS IN THE 70S TO MID 80S
FOR MOST LOCATIONS THROUGH THE WEEK AHEAD. CHAMBERS
AVIATION
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. SOUTHEAST
WINDS INCREASE TONIGHT BETWEEN 03Z AND 09Z INTO THE 25 KT TO 30 KT
RANGE BETWEEN 1000 FT TO 3000 FT POTENTIALLY CREATING LLWS AT
TIMES. OTHERWISE, MID TO HIGH LEVEL CLOUDS LOOK TO PERSIST ACROSS
THE AREA DURING THE OVERNIGHT HOURS. JW
PRELIMINARY POINT TEMP/POPS
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 053/079 057/080 053/072 048/076 051/083 055/087 057/089
02/B 41/B 55/T 10/U 00/B 12/T 22/T
LVM 045/077 047/077 044/071 041/078 045/083 047/086 049/086
06/T 72/T 33/T 10/U 01/B 12/T 22/T
HDN 052/080 055/079 050/071 046/076 048/082 052/086 054/089
03/T 62/W 47/T 10/U 01/B 12/T 22/T
MLS 051/081 055/074 050/070 047/072 047/077 051/081 054/085
02/B 77/T 37/T 11/U 00/B 11/B 33/T
4BQ 052/081 055/073 050/068 047/071 047/076 051/081 054/085
15/T 88/T 38/T 21/U 01/U 22/T 32/T
BHK 045/077 050/067 045/068 043/069 042/073 046/077 050/081
01/N 89/T 37/T 33/T 00/B 11/B 32/T
SHR 047/078 050/075 046/067 041/072 044/079 048/082 049/085
06/T 76/T 69/T 31/U 12/T 32/T 22/T
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
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